Hearth for oil burning furnaces



Jan. 19, 1932. POWERS HEARTH FbR OIL BURNING FURNACES v Filed Nov. 25.1929' INVEN TO R 7 40075725 ATTO RN EYE Patented Jan. 19,

' MILTON A. POWERS,

" COMPANY, 01 DETROIT, MICHIGAN, A

or DETROIT, MICHIGAN,

i HEARTH FOR OIL BURNING FURNACES Application filed November 25, 1928Serial No. 409,730.

The invention relates to oil burning furthat the flame lifts orrlcaASSIGNOR TO THE TIMKEN DETROIT CORPORATION OF MICHIGAN REISSUEDcompletely away from naces and has more particular reference to theconstruction of the hearth or refractory member against which the liquidfuel spray is projected. Heretofore certain hearth constructions havebeenus'ed in connection with 7 oil burnersof the rotary nozzle type inwhich an annular groove oif'eliannel is arranged adjacent to theperiphery of the hearth for the collection of a portion of the liquidfuel.

This has the advantage that after the hearth is" heated the liquid uelwhich drains into this groove orchannel will'be vaporized and will becommingledwitlii he radially propelled air current. It"has been found,however, that where the anti-tram is of considerable stren th it willsweep over the depressed surface 0 the groove carrying awa any vaporwhich may have been formed t erein without giving it time to be ignited.This is particularly true during the starting cycle 7 when the hearth iscold and the rate of. production of vapor very low. 7 Underthese'circumstances it is found that even though ignition takes place atone point in the hearth ring great difliculty ring. It is evident thatthe hearth ring the advance of vapor is'blown from the ring there willbe little or no flame propagation and ignition failure will result. Itis customary to have a vertically extending peripheral wall in rear ofthe groove which receives the sprayed oil and changes the direction ofthe commingled air and fuel vapor from the horizontal. The mixing of theair and the oil vapors and their redirection upward results inacombustible mixture which burns above the hearth ring in close proximityto the wall of the combustion-chamber. Unless special rovision is madethe upward velocity of t e vapor air mixture may exceed the rate offlame propagation downward with the consequence is encountered inpropagating the flame around the remainder of the the hearth member attimes and may remain completely extinguished at various points along thering.

It is the object of the present invention first to provide a wellrotected area alon which the vapors may a Vance to insure rapldcombustion around the entire periphery of the hearth ring. It is afurther ob ect to obtain a more thorough commingling of the fuel vaporsand air to facilitate combustion. A third and equally important objectis to provide a connected series of small areas in the combustion zonewhich will initiate combustion at all times in close proximity to theupper edge of the hearth ring and maintain ignition over each areacontinuously. With these objects in view the invention consists in theconstruction as hereinafter set forth.

In the drawings: Figure 1 1s a vertical central section through an oilburning furnace to which my improvements are applied;

Figure 2 is an enlarged cross section through a portion of the hearth,and

Figure 3 is a plan view.

As illustrated, A is a rotary oil burning nozzle of any suitableconstruction and B is the refractory hearth surrounding this burner andextending to the walls of the furnace. Supported on the peripheralportion of this hearth B is a ring G having a grooved inner ledge 13 andan upward and somewhat inwardly extending wall portion E terminating inan outwardly curved or flaring portion F. The portion F has projectingapproximately radially inward therefrom a series of spaced lugs G, theinner faces of which are substantially vertical and the top facessubstantially horizontal. These horizontal surfaces H merge with theflaring surface F at a point I to form a continuous flat top J from thispoint outward.

With the construction just described the liquid fuel spray which isdischarged radially from the rotary burner A is pro'ected against thewall portion E from which it is vaporized. The portion of the spray notimmediately vaporized drains downward into the channel I). When arunning heat balance is established there will be ractically no liquidfuel drained into the c annel D. During the starting cycle however somewill collect there but is vaporized and burned as the refractory memberbecomes heated. The air stream radiated from the burner toward thehearth ring advances in close proximity to the floor of the hearthitself. When it reaches the hearth rin it is deflected 11E- ward by theshoulder mixing with t e vapor from the groove D. However on accountof'the depth of the groove D and the interference of the shoulder K thetendency of the air current to sweep into the groove D is minimized. Theprotected area within the groove D thus serves to readily conduct vaporand consequently the flame itself from the point of i ition entirelaround the ring. Interme ate the lugs the commingle air and fuel isermitted to rise along the curved surface F ut the fact that the flatsurfaces H and J form a considerable por tion of the area will cause theformation of return eddies which hold the flame downward nearer to thehearth top. The fact that the spaced flat surfaces H are connected bythe surface J serves to readily establish and maintain burnin above eachof these surfaces. In addition the proximity of the flame to the hearthimparts a higher temperature to thehearth. with the result that theliquid fuel is more perfectly vaporized.

The construction above described can manufactured as readily as hearthconstructions which have heretofore been used and greatly increases theease of starting and general reliability and efliciency o the burner.

What I claim as my invention is:

1. The combination with a rotary oil burner nozzle provided with meansfor radially dischargin liquid fuel and air, of a refractory heartsurroundin said burner provided with an up-turne portion at itsperiphery and a depressed annular groove adjacent to this u -turnedportion for receiving a portion of e liquid fuel and means forobstructing a portion of the air current deflected by said u -turnedportion to prevent the sweeping of uel vapor from said groove and tohold the flame in proximity-thereto.

2. The combination with a rotary oil burner nozzle provided with meansfor radially dischargin liquid fuel and air, of a refractory heartsurroundin said burner provided with an up-turned edge for deflectingthe air stream upward a continuous deep groove in the lee of the led anda serrated rear wall against which e oil spray impinges, the ro'ectionsbetween serrations serving to ho d t e flame in proximity to saidgroove.

3. The combination with a rotar oil burner provided with means for raially discharging liquid fuel and air, of a hearth surrounding saidburner provided with upturned peripheral portions and a depressedannular groove or channel adjacent to this portion for receiving liquidfuel and a series of spaced lugs projecting inward from said up-turnedportion adapted to obstruct the flow to improve mixing of the airandvapors and to prevent sweepin of the vapor from said channel and toho d the flame in proximity to said groove.

4. The combination with a rotar oil burner provided with means for reially dischar 'ng liquid fuel and air, of a hearth surroun ing saidburner provided with an upturned peripheral ortion and a depressed ooveor channel a jacent thereto for receivmg liquid fuel and a series ofspaced lugs projecting inward from said up-turned portion said lulglshaving substantially flat tops and the we intermediate said lugs being'flared outward for the purpose described.

5. The combination with a rota oil burner provided with means for re'ally discharging liquid fuel and air, of a hearth surrounding saidburner, a ring supported on a peripheral portion of said hearth andhaving an inwardly extending grooved ledge mer ing into an upwardly andinwardly extending portion terminating in an outwardly flaring portion,a series 0 spaced lugs pro]ecting inward from the latter portion andhavin substantially vertical inner faces and su stantiall horizontal topfaces for the purposes descri d.

6. A combination with a rotary oil burner rovided with means forradially discharging liquid fuel and air, of a hearth surrounding saidburner a refractory ring supported upon the peripheral portion of saidhearth and comprising an inwardly extending ooved ledge merging into uwardly prcectin spaced lugs above the atter ortion rovi ed withsubstantially vertica inner aces and substantially horizontal top faces,and outwardly flaring grooves between said lugs merging into the flatupper surfaces thereof and forming a continuous flat ring be 0nd thepoint of merging.

The combination with a rotary oil burner provided with means forradially discharging liquid fuel and air, of a hearth surrounding saidburner provided with an upturned peripheral ortion and a depressedgroove or channel a jacent thereto for receivin liquid fuel, and aseries of spaced lugs on said upturned portion said-lugs havingsubstantially flat tops and the wall intermediate said lugs being flaredoutward for the purpose described.

emme 8. The combination with a rota oil bumer provide& with means for re'ally die cher ing liquid fuel anti air, of a hearth sur roun ing saidburner provided with an up turned peri heral portion and a depressedgroove or c ennei adjacent thereto for receiving liquid fuel and eseries of spececi lulge projecting inwar from said upturned por timesaid lugs forming an obstruction to e,

@ portion of the current directed upward by said upturned peripheral byretaining" the flame in groove:

In testimony whereof I afiix my signature MILTON A. POWERS;

portion and thereproximity to

